It was dark in the cave, and their lighting tools were candles bought from the master on the ecliptic mountain. If you don't light a candle after you go in, there is really no light at all. The paranormal came from browsing the photos taken in the cave after returning home, and found that there was a head on one photo, which seemed to be embedded in a stone wall and hung in the air, and the outline of the five senses was very clear.